The present application relates generally to an improved data processing apparatus and method and more specifically to mechanisms for isolation of namespace to allow duplicate or common names in a root volume group workload partitions.
A software workload partition (WPAR) provides isolation of software services, applications, and administration utilizing flexible software-defined boundaries within a single instance of an operating system. A software partition has the look and feel of a stand-alone system. A WPAR can be booted, accessed and shut down like a stand-alone machine. The very first environment, the traditional operating system (OS), on top of which WPARs are created is called “the global,” i.e. the global environment or the global operating system. Normally, for such partitions, the global stores the file system data and boot information on the local hard disks, and the global boots the WPARs from the local disks.
A WPAR shares the operating system and resources of the host data processing system. Resources accessible to the operating system of the host data processing system are said to belong to a “global space.” An application executing in a WPAR may use the WPAR as if the WPAR were a complete data processing system. The application executes in the WPAR without the awareness that the WPAR, and consequently the application, is sharing resources in the global space of the host data processing system. More than one WPAR may share resources in the global space.
A WPAR is configured, started, operated, and eventually terminated in a host data processing system using resources in the global space. Resources utilized by the WPAR during these various stages remain visible, available, and accessible to the operating system of the host data processing system.
A WPAR should support physical storage devices. Once a device has been exported to a WPAR, the WPAR must have exclusive control over the device. The device can be “varied on” and “varied off” from within the WPAR without affecting the global. To “vary on” a device is to activate the device for use. Conversely, to “vary off” a device is to deactivate the device. New logical volumes can be created on the device.